From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: [PATCH v2 14/18] lib/test_lockup: fix kernel pointer check for separate address spaces Date: Wed, 16 Feb 2022 14:13:28 +0100 Message-ID: <20220216131332.1489939-15-arnd@kernel.org> References: <20220216131332.1489939-1-arnd@kernel.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=5JrwkZZCRtbw8Bh1EEeOMQpcvVWSTDmy6nfhAQLcAvQ=; b=lj+wkwFs8ldF5x u2rdqQj8KYTdN2jNXf2Qlq24pWlGXkIlVDR7gnTeUEJkA6XSFXPas0NDoRw/14l1Ju4RBwIj0ER2b 1T+axOgifO0a+LjDhG1FukzabGlEN1p+MoS0wQnK8Y+bNK+66wBCKo48JniYzEQaRxzA/DKyS1lys OWU6RBbjO5HJNkDEBzbb4JaUvszMzt03tCHluRwXu0FjFvNk5K6DE6/V52a4ev6Zguh62YPhJZHlJ OTCEDMTEaNzHO8TYNzK5iVd9MNj6vKgBIsTogs/FCspI4BK+qtJcewJ44+FF1pwwss2v036Byj40+ 1T6rOpLk9pggGFy+j/lQ==; DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1645017484; bh=VX4KkQyuIR3tQGDR6prM8ou6pbxkhf/vAdqGON90Cm0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=CHCgfRQJGdosNV1evKFnaA5ei4xJAQnutJJPhJDJedQb8ubdZ/7Y4gbjZfBoHlpfu 02zUcTsVmwftwP3VFFw8cf1xplYfxud05Hq90fcOl+6pChvWJp2VuJGg6f1dhDmeKP 2Ku7d6y9bCG/B7QQIkLEQll/VqhOb3oxvRxpjL7bHiIP7fh7rr3NkfNXH+hMaXbIfa qHFBF3xOTCoSqLhRyub3LajzF4xQe4lV+XRk2zeVmUEYrZWjONVkWPfTimkvr5qUGC VogArIAmhrmBKTIWZOEA4fZwuT8tCTP8ztaTT853tTOy2yqxBDNJ8/RxehDqdkvFhY Yb158iS57sWQQ== In-Reply-To: <20220216131332.1489939-1-arnd@kernel.org> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+glpr-linux-riscv=m.gmane-mx.org@lists.infradead.org To: Linus Torvalds , Christoph Hellwig , linux-arch@vger.kernel.org, linux-mm@kvack.org, linux-api@vger.kernel.org, arnd@arndb.de, linux-kernel@vger.kernel.org, viro@zeniv.linux.org.uk Cc: linux@armlinux.org.uk, will@kernel.org, guoren@kernel.org, bcain@codeaurora.org, geert@linux-m68k.org, monstr@monstr.eu, tsbogend@alpha.franken.de, nickhu@andestech.com, green.hu@gmail.com, dinguyen@kernel.org, shorne@gmail.com, deller@gmx.de, mpe@ellerman.id.au, peterz@infradead.org, mingo@redhat.com, mark.rutland@arm.com, hca@linux.ibm.com, dalias@libc.org, davem@davemloft.net, richard@nod.at, x86@kernel.org, jcmvbkbc@gmail.com, ebiederm@xmission.com, akpm@linux-foundation.org, ardb@kernel.org, linux-alpha@vger.kernel.org, linux-snps-arc@lists.infradead.org, linux-csky@vger.kernel.org, linux-hexagon@vger.kernel.org, linux-ia64@vger.kernel.org, linux-m68k@lists.linux-m68k.org, linux-mips@vger.kernel.org, openrisc@lists.librecores.org, linux-parisc@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, linux-sh@vger.k From: Arnd Bergmann test_kernel_ptr() uses access_ok() to figure out if a given address points to user space instead of kernel space. However on architectures that set CONFIG_ALTERNATE_USER_ADDRESS_SPACE, a pointer can be valid for both, and the check always fails because access_ok() returns true. Make the check for user space pointers conditional on the type of address space layout. Signed-off-by: Arnd Bergmann --- lib/test_lockup.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/lib/test_lockup.c b/lib/test_lockup.c index 6a0f329a794a..c3fd87d6c2dd 100644 --- a/lib/test_lockup.c +++ b/lib/test_lockup.c @@ -417,9 +417,14 @@ static bool test_kernel_ptr(unsigned long addr, int size) return false; /* should be at least readable kernel address */ - if (access_ok((void __user *)ptr, 1) || - access_ok((void __user *)ptr + size - 1, 1) || - get_kernel_nofault(buf, ptr) || + if (!IS_ENABLED(CONFIG_ALTERNATE_USER_ADDRESS_SPACE) && + (access_ok((void __user *)ptr, 1) || + access_ok((void __user *)ptr + size - 1, 1))) { + pr_err("user space ptr invalid in kernel: %#lx\n", addr); + return true; + } + + if (get_kernel_nofault(buf, ptr) || get_kernel_nofault(buf, ptr + size - 1)) { pr_err("invalid kernel ptr: %#lx\n", addr); return true; -- 2.29.2